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Kimi K2.5 (OpenRouter) vs Llama 3.1 405B (Together AI): API Cost Comparison

Compare the API pricing, context windows, features, and real-world cost projections for Kimi K2.5 (OpenRouter) (OpenRouter) and Llama 3.1 405B (Together AI) (Together AI). Use the interactive calculator below to compute your exact monthly cost based on your token usage and request volume.

Prices verified Mar 10, 2026

Interactive Cost Calculator

OpenRouterKimi K2.5 (OpenRouter)Together AILlama 3.1 405B (Together AI)

Fills in typical token counts for a workload type

Tokens in each prompt sent to the model

Tokens generated in each response

Total API calls per month

Showing costs for 2 models. Cheapest: Kimi K2.5 (OpenRouter) at $15.50/month.

Cheapest: Kimi K2.5 (OpenRouter) at $15.50/mo — save 70.5% vs Llama 3.1 405B (Together AI)
Alert
BestKimi K2.5 (OpenRouter)
OpenRouter$15.50$0.001550$4.50$11.0070.5%Alerts coming soon
Llama 3.1 405B (Together AI)
Together AI$52.50$0.005250$35.00$17.50Alerts coming soon

Monthly Cost Comparison

Price Comparison at a Glance

All prices are in USD per 1 million tokens ($/M tokens). Lower is cheaper.

Pricing TypeKimi K2.5 (OpenRouter)Llama 3.1 405B (Together AI)Cheaper
Input (standard)$0.45/M$3.50/MKimi K2.5 (OpenRouter)
Output$2.20/M$3.50/MKimi K2.5 (OpenRouter)

Prices last verified: 2026-03-06 – 2026-03-10

Cost Breakdown by Usage Volume

Estimated monthly costs at different request volumes, assuming 1,000 input tokens and 500 output tokens per request. Adjust in the calculator above for your specific use case.

VolumeKimi K2.5 (OpenRouter)MonthlyLlama 3.1 405B (Together AI)MonthlyKimi K2.5 (OpenRouter)Per requestLlama 3.1 405B (Together AI)Per request
1K requests/mo$1.55$5.25$0.001550$0.005250
10K requests/mo$15.50$52.50$0.001550$0.005250
100K requests/mo$155.00$525.00$0.001550$0.005250
1M requests/mo$1,550.00$5,250.00$0.001550$0.005250

Green values indicate the lower-cost option at each volume tier. Cost per request is calculated at 1,000 input + 500 output tokens using standard (non-batch, non-cached) pricing.

Price History

Input price per 1M tokens

When to Choose Kimi K2.5 (OpenRouter)

by OpenRouter

  • Document summarization
  • General chatbot
  • RAG / Semantic search

Input / 1M tokens

$0.45/M

Output / 1M tokens

$2.20/M

Context window

262,144

Tier

mid

When to Choose Llama 3.1 405B (Together AI)

by Together AI

  • Code generation
  • Content & copywriting
  • Document summarization

Input / 1M tokens

$3.50/M

Output / 1M tokens

$3.50/M

Context window

131,072

Tier

premium

Key Differences Beyond Price

Cost is only one factor in choosing an AI model. Context window size, rate limits, supported features, and latency all affect whether a model fits your use case.

CapabilityKimi K2.5 (OpenRouter)Llama 3.1 405B (Together AI)
Context window262,144 tokens131,072 tokens
Max output tokens65,535 tokens4,096 tokens
Performance tierMidPremium
Vision / image inputNoNo
Function callingYesYes
JSON modeYesYes
Prompt cachingNoNo
Batch API (50% discount)NoNo
Extended reasoningNoNo
Fine-tuningNoNo

Kimi K2.5 (OpenRouter) notes

OpenRouter offers 200+ models — showing top 15 unique models not available from other listed providers. Prices include OpenRouter markup.

Llama 3.1 405B (Together AI) notes

Largest open-source model available via API. Meta license allows commercial use.

Frequently Asked Questions

Is Kimi K2.5 (OpenRouter) cheaper than Llama 3.1 405B (Together AI)?

At standard usage (1,000 input tokens, 500 output tokens, 100,000 requests/month), Kimi K2.5 (OpenRouter) costs $155.00/month versus $525.00/month for Llama 3.1 405B (Together AI) — a 70% saving. Your actual savings will vary based on your token profile; output-heavy workloads amplify differences in output pricing.

Which model has a larger context window, Kimi K2.5 (OpenRouter) or Llama 3.1 405B (Together AI)?

Kimi K2.5 (OpenRouter) has a larger context window at 262,144 tokens, compared to 131,072 tokens for Llama 3.1 405B (Together AI). A larger context window is important for processing long documents, multi-turn conversations, or large codebases without truncation.

Do Kimi K2.5 (OpenRouter) and Llama 3.1 405B (Together AI) support the Batch API?

Neither Kimi K2.5 (OpenRouter) nor Llama 3.1 405B (Together AI) currently supports a batch API with discounted pricing. For batch-eligible alternatives, consider models from OpenAI, Anthropic, or Google that include batch API support.

Which model offers better prompt caching?

Neither Kimi K2.5 (OpenRouter) nor Llama 3.1 405B (Together AI) currently supports prompt caching. For prompt-caching capable alternatives, consider Claude models from Anthropic or GPT-4o from OpenAI.

What are the best use cases for Kimi K2.5 (OpenRouter) vs Llama 3.1 405B (Together AI)?

Both models are well-suited for Document summarization. Kimi K2.5 (OpenRouter) is particularly strong for General chatbot, RAG / Semantic search. Llama 3.1 405B (Together AI) is favored for Code generation, Content & copywriting. At the same quality level, the lower-cost model is usually preferable; use this page's calculator to compare total monthly spend at your volume.

What is the cost per request for Kimi K2.5 (OpenRouter) vs Llama 3.1 405B (Together AI)?

At 1,000 input tokens and 500 output tokens per request — a typical conversational workload — Kimi K2.5 (OpenRouter) costs $0.001550 per request and Llama 3.1 405B (Together AI) costs $0.005250 per request. At 100,000 requests/month, that translates to $155.00 and $525.00 respectively. Use the interactive calculator to adjust these parameters for your actual workload.

Kimi K2.5 (OpenRouter) vs Llama 3.1 405B (Together AI): Summary

When comparing Kimi K2.5 (OpenRouter) and Llama 3.1 405B (Together AI) for API cost, the right choice depends on your workload's token profile, required features, and tolerance for latency. Kimi K2.5 (OpenRouter) offers lower total cost at standard usage volumes (1,000 input + 500 output tokens per request at 100,000 requests/month) at $155.00/month, compared to $525.00/month for Llama 3.1 405B (Together AI).

Both models are priced in USD per million tokens, the standard unit across all major AI API providers. Kimi K2.5 (OpenRouter) charges $0.45/M for input tokens and $2.20/M for output tokens. Llama 3.1 405B (Together AI) charges $3.50/M input and $3.50/M output. If your workload is output-heavy (more tokens generated than consumed as input), the model with the lower output price compounds cost savings significantly at scale.

Context window capacity differs between the two: Kimi K2.5 (OpenRouter) supports up to 262,144 tokens in a single request, versus 131,072 tokens for Llama 3.1 405B (Together AI). A larger context window is essential for document summarization, large codebase analysis, and multi-document retrieval-augmented generation (RAG) applications.

Use the interactive calculator at the top of this page to enter your actual token usage and monthly request volume for a precise cost comparison tailored to your workload. Adjust for batch API discounts and prompt caching to find the most cost-effective option for your specific deployment.

Explore other model comparisons from the same providers or performance tiers.

Related Provider Pages

View complete pricing tables and model lineups for the providers behind these models.

Relevant Use Cases

See cost recommendations for workloads where Kimi K2.5 (OpenRouter) or Llama 3.1 405B (Together AI) is recommended.